Comprbssoe lubrication during reverse rotation



Mamh 2%, 3%? R. F. CONNOR 3,311,292

COMPRESSOR LUBRICATION DURING REVERSE ROTATION Filed June 30, 1965 2 Sheets-Sheet 1 March 28, N67 R. F. CONNOR 3,331,292

COMPRESSOR LUBRICATION DURING REVERSE ROTATION Filed June 30, 1965 2 Sheets-Sheet 2 United States Patent 3,3113% CQMPRESSQR LUBEICA'IION DURING REVERSE RQTATIGN Ralph F. Connor, Evansville, Ind, assignor to Whirlpool Corporation, a corporation of Delaware Filed .lune 3d, 1965, Ser. No. 468,483 9 Claims. (61. 23tl207) This invention relates to compressors and in particular to lubrication means for use in rotary compressors.

In refrigeration apparatus and the like, rotary compressors are conventionally employed for providing compression of the refrigerant fiuid as one step of the refrigeration cycle. Such compressors are normally operated in a single direction of rotation. conventionally, such compressors are lubricated by self-contained lubrication pump means. It has been found, however, that under certain circumstances, the compressor may be caused to function inadvertently in a reverse direction, thereby causing a malfunctioning of the lubrication pump means and seriously damaging the compressor.

Illustratively, in one form of conventional compressor, the compressor is provided with a three-phase electric motor which may be caused to operate in either direction of rotation by selective connection of the three-phase power supply leads to the terminals thereof. In certain instances, the motor leads may be incorrectly connected during installation or a change in the phase sequence of the power supply may occur subsequent to the installation of the compressor so that reverse operation my be caused. It has been found that improper reverse operation wherein the lubrication means is inefiective may cause serious damage to such a compressor after only two or three cycles of rotation. Thus, it is highly desirable to provide in such a compressor means for effectively precluding undesirable lubrication failure in the event of a reverse op eration of the compressor.

A principal feature of the present invention is the provision of a new and improved lubrication means for use in such rotary compressors preventing damage to the compressor upon operation thereof in a direction opposite to the normal direction of operation.

A further feature of the invention is the provision of such a lubrication means arranged for proper operation in either the forward or reverse directions of rotation of the compressor.

Another feature of the invention is the provision of such a lubrication means which is extremely simple and economic-a1 of construction while yet providing long trouble-free reversible pumping of the lubrication fluid.

A yet further feature of the invention is the provision of such a lubrication means comprising wall means defining a pump chamber having first and second contiguous portions, the wall means defining in the first portion an annular channel opening toward the second chamber portion, the channel having a radially inset portion, an inlet from the supply opening to the channel diametrically opposite the inset portion, and an outlet to the lubrication requiring means at a radially innermost portion of the inset portion of the channel, and fluid impeller means in the second portion of the chamber for causing oil entering the channel through the inlet opening to fill the chamber to move through the channel and pass therefrom through the outlet.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a diametric section of a compressor provided with a lubrication means embodying the invention;

FIGURE 2 is a fragmentary enlarged section illustrating the lubrication means in greater detail;

FIGURE 3 is a horizontal section taken substantially along the line 3-3 of FIGURE 2;

FIGURE 4 is a fragmentary horizontal section taken substantially along the line 4 4 of FIGURE 2; and

FIGURE 5 is a fragmentary isometric view of the bottom wall member illustrated in FIGURE 4.

In the exemplary embodiment of the invention as disclosed in the drawing, a compressor generally designated Ill is shown to comprise a rotary compressor such as for use in refrigeration apparatus having a suction conduit 11 for delivering refrigerant vapor to the compressor and a discharge conduit 12 for conducting the compressed refrigerant from the compressor. The compressor includes a rotor 13 disposed in a pump chamber 14 and carried on a shaft 15 driven by an electric motor :16 for rotation of the rotor suitably to compress refrigerant delivered to the chamber 14 from the suction conduit 11.

The compressor includes an outer housing 17 which is hermetically closed. As shown in FIGURE 1, motor 16 is disposed in the upper portion of the space 18 within housing 17 and includes a stator 19 and an armature 20', the armature being carried on the upper end of the shaft 15 for rotation thereof about the vertical axis of the housing 17. That portion of shaft 15 above the rotor 13 is suitably journalled in a bearing 21 mounted on the compressor mechanism 22 which in turn is carried on a support 23 fixedly secured to the bottom wall 2-? of the housin 17. Likewise, that portion of shaft 15 below the rotor is suitably journalled in a bearing located in rear head block 33. All of these bearings require adequate lubrication during operation of the compressor, and the means for accomplishing such lubrication will be hereinafter described.

The lower portion of the housing 17 defines a sump 25 in which a body of lubricant, such as lubricating oil 26, is provided. The oil is pumped upwardly from the sump 25 by means of a pumping apparatus 27 provided at the lower end of the shaft 15. As best seen in FIGURE 2, the support 23 is provided with an opening 28 aligned with a passage 29 extending through a lower wall member defining a cover plate 3%. The passage 29 comprises an inlet opening to an annular channel 31 in the upper surface 32 of the wall member 30. Carried on the upper surface 32 is a rear head block 33 which sup ports the rotor housing 34 and which is provided with a downwardly opening cylindrical recess 35 which cooperates with the annular channel 31 to define a pump chamber 36. An impeller 37 is carried on the lower end of shaft 15 for rotation coaxially within recess 35 with the lower surface 38 of the impeller slidably engaging the surface 32 of the lower wall member 30. The block 33 may be provided with 21 depending annular boss 39 spaced adjacent shaft 15 to slidably bear against the upper surface it} of the impeller 37, thereby completing the enclosure of the pump chamber 36.

As shown in FIGURE 3, the impeller 37 may comprise a gear pump rotor having a plurality of symmetrical teeth 41. As the rotor is rotated ooaxially within the recess 35 defining the upper portion of chamber 36, oil in the chamber is moved annularly through the cham* ber including not only the oil in chamber portion 35 but also the oil in the subjacent portion 31 defined by the annular reccess in wall member 3%).

The configuration of the annular channel 31 in wall member 343 is best seen with reference to FIGURES 4 and 5. As shown, the channel 31 opens upwardly through the upper surface 32 and is relatively shallow. The channel includes a first cylindrical portion 42 which extends coaxially of the rotor shaft 15 approximately degrees symmetrically to either side of the diametric plane taken through the center of the shaft 15 and the 3 center of the inlet opening 29. The portion of channel 31 diametrically opposite the inlet opening 29 comprises an inset portion 43 including an inner space 4 at the inner end thereof and coaxially aligned with the lower end of the shaft 15. As shown in FIGURE 2, the lower end of the shaft 15 is provided with a downwardly opening cylindrical recess 45 communicating with space 4-4. Thus, recess 45 and inner space 44 cooperatively define an outlet 47 for discharging the lubricating oil from the pump means 27 upwardly through a suitable oil passage 43 in the rotor shaft 15.

As best seen in FIGURES l and 2, vertically aligned oil grooves 49 are provided in the lower end of shaft 15 for conducting a portion of the pressurized oil from oil passage 48 to a cylindrical space surrounding the lower end of the shaft 15 radially inwardly of the annula-r boss 39 of block 33. The oil in grooves 49 supplies lubrication to the engaging surfaces of the shaft 15 and lower bearing 65. Oil reaching space is conducted back to the sump 25 through a return passage 51 in block 33.

Again referring to FIGURE 1, another portion of the pressurized oil within passage 48 passes to vertically extending oil grooves 66 located on the exterior surface of the upper end of shaft 15. Further, oil leaving grooves 66 communicates with vertically extending up per grooves 67, on the exterior surface of shaft 15, via the reduced diameter portion 68 of the shaft 15. Thus, the oil in grooves 66 and 67 and in reduced diameter portion 68 provides adequate lubrication for the engaging surfaces of the shaft and the upper (bearing 21. The upper terminal ends of grooves 67 communicate with space 18 thereby providing means for returning to the sump that oil which leaves grooves 67. The vertical disposition of oil grooves 4-9, 66 and 67 is desirable since the oil can freely move upwardly through the bearing surfaces regardless of the direction of rotation.

The inset portion 43 of channel 31 is defined by an inwardly projecting bathe 52 comprising an inward projection of the outer surface 53 of the channel 31. More specifically, as best seen in FIGURE 4, the baffle 52 is symmetrical about the diametric plane through the centers of inlet 29 and outlet 47. Each side of the baffle is defined by a relatively small radius, cylindrical portion 54 joining smoothly with the relatively large cylindrical portion 53 of the channel 31 and a planar surface 55 extending generally parallel to the diametric plane through the centers of inlet 29 and outlet 47. The tip 56 of the baffle, as shown in FIGURE 4, is cylindrical, having a very small radius.

The inner surface 57 of the channel includes a cylindrical portion 58 extending approximately 150 degrees to each side of the above described diametric plane. At inset portion 43 of the channel 31, the surface 57 is defined by a pair of planar surface portions 59 converging toward the inlet 29 and joined at their inner ends by a cylindrical surface 60 concentric to and having a radius slightly larger than that of recess 45 within shaft 15. Thus, bafile 52 provides a smoothly inturned outlet portion 43 of the channel 31 leading to the outlet 47 for either direction of flow of the oil from the inlet to the outlet.

Thus, for example, assuming that motor 16 is operated to rotate the gear 37 in a clockwise direction, as shown in FIGURE 3, oil will be pumped from the inlet 29 through the righthand portion of the channel 31 to the outlet 47, as shown in FIGURE 3. Alternatively, if the motor 16 is operated to rotate the gear in a counterclockwise direction, oil is pumped from the inlet 29 through the left hand portion of the channel 31 to the outlet 47, as shown in FIGURE 3. The bafiie conducts the oil smoothly into the outlet portion of the channel providing an efficient pumping action irrespective of the direction of rotation of the motor.

In the illustrated embodiment, the tip 56 of the bafiie 52 is disposed radially within the inset portion 43 defined by the inwardly converging planar surfaces 59 of the surface 57. It has been found, however, that efiicient reversible operation of the pump maybe effected with a lesser inward projection of the bafile. The impeller in the preferred embodiment has been shown herein as a gear type impeller having a plurality of symmetrical teeth 41. It will be readily understood that an impeller having teeth which are not symmetrical could likewise be employed wherein the oil flow rate during reverse rotation would be reduced, but still sufiicient as compared to the flow rate obtained during normal rotation. As is likewise obvious to those skilled in the art, other suitable symmetrical types of impellers may be employed for causing the desired flow of the oil through the channel 31. While I have shown and described one embodiment of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim: 1. In a rotary compressor having a lubricating oil supply and means requiring lubrication, apparatus for providing oil from the supply to said means, comprising: wall means defining a pump chamber having first and second contiguous portions, said wall means defining in said first chamber portion an annular channel opening toward said second chamber portion, said channel having a first portion and an inlet from said supply opening to said channel at a second portion diametrically opposite said first channel portion;

means defining an outlet to said lubrication requiring means communicating with said channel radially inwardly of said first channel portion;

fluid impeller means in said second chamber portion;

means for rotating said impeller means about a fixed axis in either of opposite directions of rotation for causing oil entering said channel through said inlet opening to fill said chamber and move in either annular direction through said channel to said first channel portion; and

deflection means in said first channel portion for directing lubricating oil radially inwardly to said outlet as an incident of flow thereof in either annular direction from said inlet to said first channel portion.

2. The rotary compressor of claim 1 wherein said channel is symmetrical about a diametric plane through the center of each of said inlet and outlet.

3. The rotary compressor of claim 1 wherein said outlet opening is at the center of radius of said annular channel.

4. The rotary compressor of claim 1 wherein said channel has a radially inner surface and a radially outer surface, said outlet means being defined by a radially inwardly extending recess in said inner surface and an inward projection of said outer surface extending to within said recess.

5. The rotary compressor of claim 1 wherein said deflection means comprises a radially inwardly projecting fixed baffle.

6. The rotary compressor of claim 1 wherein said channel has an outer surface provided with an inward projection at said first portion, said projection defining said deflection means and being symmetrical about a diametric plane through the center of said inlet and outlet and having a curved radially outer portion and a planar inner portion extending substantially parallel to said diametric plane.

7. The rotary compressor of claim 1 wherein said channel has a radially inward surface defining a recess having planar sides converging toward said outlet.

3. The rotary compressor of claim 1 wherein said second portion of the chamber is right circularly cylindrical and said fluid impeller comprises a toothed wheel essentially rotatable therein.

5 6 9. In a rotary compressor having a lubricating oil supchamber causing oil entering said channel through ply and means requiring lubrication, apparatus for prosaid inlet opening to fill said chamber to move viding oil from the supply to said means, comprising: through said channel and pass therefrom through first Wall means defining an annular channel; said outlet. second wall means defining an annular space communi- 5 eating With said annular channel and defining there- References Cited y the Examine! With a pump chamber, said channel having a radial- UNITED STATES PATENTS ly inset portion, an inlet from said supply opening to said channel diametrically opposite said insert 2107152 2/1938 Huber portion, and an outlet to said lubrication requiring 10 i 2 g 230 58 means at a radially innermost portion of said inset 3039677 6/1962 gg 230, 206

portion of the channel; and fiuid impeller means in said second portion of the ROBERT M. WALKER, Plilfltll) Examiner. 

1. IN A ROTARY COMPRESSOR HAVING A LUBRICATING OIL SUPPLY AND MEANS REQUIRING LUBRICATION, APPARATUS FOR PROVIDING OIL FROM THE SUPPLY TO SAID MEANS, COMPRISING: WALL MEANS DEFINING A PUMP CHAMBER HAVING FIRST AND SECOND CONTIGUOUS PORTIONS, SAID WALL MEANS DEFINING IN SAID FIRST CHAMBER PORTION AN ANNULAR CHANNEL OPENING TOWARD SAID SECOND CHAMBER PORTION, SAID CHANNEL HAVING A FIRST PORTION AND AN INLET FROM SAID SUPPLY OPENING TO SAID CHANNEL AT A SECOND PORTION DIAMETRICALLY OPPOSITE SAID FIRST CHANNEL PORTION; MEANS DEFINING AN OUTLET TO SAID LUBRICATION REQUIRING MEANS COMMUNICATING WITH SAID CHANNEL RADIALLY INWARDLY OF SAID FIRST CHANNEL PORTION; FLUID IMPELLER MEANS IN SAID SECOND CHAMBER PORTION; MEANS FOR ROTATING SAID IMPELLER MEANS ABOUT A FIXED AXIS IN EITHER OF OPPOSITE DIRECTIONS OF ROTATION FOR CAUSING OIL ENTERING SAID CHANNEL THROUGH SAID INLET OPENING TO FILL SAID CHAMBER AND MOVE IN EITHER ANNULAR DIRECTION THROUGH SAID CHANNEL TO SAID FIRST CHANNEL PORTION; AND DEFLECTION MEANS IN SAID FIRST CHANNEL PORTION FOR DIRECTING LUBRICATING OIL RADIALLY INWARDLY TO SAID OUTLET AS AN INCIDENT OF FLOW THEREOF IN EITHER ANNULAR DIRECTION FROM SAID INLET TO SAID FIRST CHANNEL PORTION. 